Cellulose is a basic component constituting a cell membrane and a xylem, and a type of an organic compound contained in a plant at approximately 30% or more. The cellulose is a polysaccharide with a chemical structure consisting of a plurality of D-glucose units linked by a β-1,4 glycoside bond, and a molecular weight of several tens of thousands to several hundreds of thousands in a natural state. The cellulose is a white odorless solid and insoluble in water, ethanol and ether, and has a considerably strong resistance to an alkali. However, the cellulose is hydrolyzed in an acid or cuprammonium solution, thereby producing a great quantity of cellobiose as an intermediate, and is finally converted into glucose. Since the cellulose is one of the most abundant natural resources in nature, many studies for utilizing it are progressing.
Meanwhile, cellulase that decomposes cellulose has a cellulose binding domain (CBD), and thus specifically binds to cellulose to effectively decompose it. There have been various attempts to produce a recombinant protein specifically binding to cellulose by binding such a cellulose binding domain to a target protein (Korean Patent No. 10-0618563). However, such attempts are limited to methods of producing a recombinant protein using a microorganism, and an example using plants has not been reported.
However, recently, since attention is focused on production of plant-derived recombinant proteins or vaccines, development of a method of producing a great quantity of recombinant proteins using plants, and rapidly isolating a high purity recombinant protein in large quantities at low cost is urgently needed.